As much as I love roses, I really don't like most rose perfumes. As with many flowers, when you smell them in nature there's a lot of nuance to their scent, though when replicated synthetically, or even captured in the form of an essential oil or absolute, the concentrated fragrance only gives a snapshot of the living flower from one perspective.
Pure DKNY A Drop of Rose is the cut flower with all of its stem and leaves sitting in the florist's fridge - it's a green and chilly rose. It's much more tart and green than sweet, yet maybe because of its gentler concentration, it doesn't veer into the head-splitting tartness of L'Occitaine's 4 Reines, or Chloe. It seems to last on my skin longer than it does for some others, though it does wear like an EDT when worn alone.
I don't wear it alone often - I tend to layer it with other scents when I want to give them a little extra rosy oomph. For that purpose I find that it's especially lovely, and has a kind of transparency and neutrality that enable it to blend really well. It lasts for at least several hours when anchored by a heavier scent.
I think this one's the best of the Pure DKNY scents so far. The others strike me as kind of pale and formless as opposed to sheer.